Backlight assembly and liquid crystal display having the same

Abstract

A back light assembly includes: a light source including a light emitting diode which generates white light having color coordinates located on one of a plurality of color coordinate ranks; a reflector sheet which reflects the white light incident from the light source, where the reflector sheet includes a reflective material which reflects light incident thereon and a color compensation material which compensates the color coordinates of the white light by controlling the intensity of light having a predetermined wavelength range, among the white light, to allow the color coordinates of the white light to converge on target color coordinates; and a diffuser plate which diffusing light provided from the light source and the reflector sheet.

What is claimed is: 
     
         1 . A back light assembly comprising:
 a light source comprising a light emitting diode which generates white light having color coordinates located on one of a plurality of color coordinate ranks;   a reflector sheet which reflects the white light incident from the light source, wherein the reflector sheet comprises:
 a reflective material which reflects light incident thereon; and 
 a color compensation material which compensates the color coordinates of the white light by controlling intensity of light having a predetermined wavelength range, among the white light, to allow the color coordinates of the white light to converge on target color coordinates; and 
   a diffuser plate which diffuses light provided from the light source and the reflector sheet.   
     
     
         2 . The back light assembly of  claim 1 , wherein the color compensation material comprises absorption pigments which absorb the light having the predetermined wavelength among the white light. 
     
     
         3 . The back light assembly of  claim 2 , wherein
 an x-coordinate value of the color coordinates of the white light is less than an x-coordinate value of the target color coordinates or a y-coordinate value of the color coordinates of the white light is less than a y-coordinate value of the target color coordinates, and   the absorption pigments increase at least one of the x-coordinate value and the y-coordinate value of the color coordinates of the white light.   
     
     
         4 . The back light assembly of  claim 3 , wherein the absorption pigments absorb light having a wavelength in a range from about 350 nanometers to about 500 nanometers, among the white light. 
     
     
         5 . The back light assembly of  claim 4 , wherein an absorption spectrum of the absorption pigments has absorption intensity of about 10% or less of maximum absorption intensity of the absorption pigments, at a wavelength of about 500 nanometers. 
     
     
         6 . The back light assembly of  claim 3 , wherein an absorption spectrum of the absorption pigments overlaps at least a portion of a blue light emitting spectrum among light emitting spectrums of the light emitting diode. 
     
     
         7 . The back light assembly of  claim 6 , wherein
 the light emitting diode generates light having a wavelength in a range from about 430 nanometers to about 450 nanometers,   a wavelength of the absorption pigments having maximum absorption intensity is within a range from about 430 nanometers to about 450 nanometers, and   a half width of the absorption spectrum of the absorption pigments is in a range from about 15 nanometers to about 30 nanometers.   
     
     
         8 . The back light assembly of  claim 2 , wherein the absorption pigments comprise azo pigments, phthalocyanine pigments, dye mordant pigments, condensed polycyclic pigments, or a combination thereof. 
     
     
         9 . The back light assembly of  claim 2 , wherein
 an x-coordinate value of the color coordinates of the white light is greater than an x-coordinate value of the target color coordinates or a y-coordinate value of the color coordinates of the white light is greater than a y-coordinate value of the target color coordinates, and   the absorption pigments reduce at least one of the x-coordinate value and the y-coordinate value of the color coordinates of the white light.   
     
     
         10 . The back light assembly of  claim 9 , wherein the absorption pigments absorb light having a wavelength in a range from about 500 nanometers to about 800 nanometers among the white light. 
     
     
         11 . The back light assembly of  claim 1 , wherein the color compensation material comprises a fluorescent body. 
     
     
         12 . The back light assembly of  claim 11 , wherein
 an x-coordinate value of the color coordinates of the white light is less than an x-coordinate value of the target color coordinates or a y-coordinate value of the color coordinates of the white light is less than a y-coordinate value of the target color coordinates, and   the fluorescent body increases at least one of the x-coordinate value and the y-coordinate value of the color coordinates of the white light.   
     
     
         13 . The back light assembly of  claim 12 , wherein the fluorescent body generates light comprising light having a wavelength in a range from about 500 nanometers to about 800 nanometers. 
     
     
         14 . The back light assembly of  claim 11 , wherein
 an x-coordinate value of the color coordinates of the white light is greater than an x-coordinate value of the target color coordinates or a y-coordinate value of the color coordinates of the white light is greater than a y-coordinate value of the target color coordinates, and   the fluorescent body reduces at least one of the x-coordinate value and the y-coordinate value of the color coordinates of the white light.   
     
     
         15 . The back light assembly of  claim 14 , wherein the fluorescent body generates light comprising light having a wavelength in a range from about 350 nanometers to about 500 nanometers. 
     
     
         16 . The back light assembly of  claim 1 , wherein
 the color compensation material of the reflector sheet defines a color compensation layer, and   the color compensation layer defines a surface of the reflector sheet.   
     
     
         17 . The back light assembly of  claim 1 , wherein the color compensation material is disposed inside of the reflector sheet. 
     
     
         18 . The back light assembly of  claim 1 , wherein the light source is disposed between the reflector sheet and the diffuser plate and provides the white light to a bottom surface of the diffuser plate. 
     
     
         19 . A liquid crystal display apparatus comprising:
 a liquid crystal display panel which displays an image, wherein the liquid crystal display panel comprises:
 an array substrate; 
 a counter substrate disposed opposite to the array substrate; and 
 a liquid crystal layer disposed between the array substrate and the counter substrate; and 
   a back light assembly which provides light to the liquid crystal display panel, wherein the back light assembly comprises:
 a light source comprising a light emitting diode which generates white light having color coordinates located on one of a plurality of color coordinate ranks; 
 a reflector sheet which reflects the white light incident from the light source, wherein the reflector sheet comprises:
 a reflective material which reflects light incident thereon; and 
 a color compensation material which compensates the color coordinates of the white light by controlling intensity of light having a predetermined wavelength range, among the white light, to allow the color coordinates of the white light to converge on target color coordinates; and 
 
 a diffuser plate which diffuses light provided from the light source and the reflector sheet. 
   
     
     
         20 . The liquid crystal display apparatus of  claim 19 , wherein the color compensation material comprises one of absorption pigments, which absorbs light having the predetermined wavelength among the white light, and a fluorescent body.